2,658 research outputs found

    Polarization Observations with the Cosmic Background Imager

    Get PDF
    We describe polarization observations of the CMBR with the Cosmic Background Imager, a 13 element interferometer which operates in the 26-36 GHz band from Llano de Chajnantour in northern Chile. The array consists of 90-cm Cassegrain antennas mounted on a steerable platform which can be rotated about the optical axis to facilitate polarization observations. The CBI employs single mode circularly polarized receivers which sample multipoles from ℓ~400 to ℓ~4250. The instrumental polarization of the CBI was calibrated with 3C279, a bright polarized point source which was monitored with the VLA

    A Multi-wavelength Study of the Host Environment of SMBHB 4C+37.11

    Get PDF
    4C+37.11, at z=0.055 shows two compact radio nuclei, imaged by VLBI at 7mas separation, making it the closest known resolved super-massive black hole binary (SMBHB). An important question is whether this unique object is young, caught on the way to a gravitational in-spiral and merger, or has `stalled' at 7pc. We describe new radio/optical/X-ray observations of the massive host and its surrounding X-ray halo. These data reveal X-ray/optical channels following the radio outflow and large scale edges in the X-ray halo. These structures are promising targets for further study which should elucidate their relationship to the unique SMBHB core.Comment: To appear in the Astrophysical Journa

    Effect of Architecture and Porosity on Mechanical Properties of Borate Glass Scaffolds Made by Selective Laser Sintering

    Get PDF
    The porosity and architecture of bone scaffolds, intended for use in bone repair or replacement, are two of the most important parameters in the field of bone tissue engineering. The two parameters not only affect the mechanical properties of the scaffolds but also aid in determining the amount of bone regeneration after implantation. Scaffolds with five different architectures and four porosity levels were fabricated using borate bioactive glass (13-93B3) using the selective laser sintering (SLS) process. The pore size of the scaffolds varied from 400 to 1300 μm. The compressive strength of the scaffolds varied from 1.7 to 15.5 MPa for porosities ranging from 60 to 30%, respectively, for the different architectures. Scaffolds were soaked in a simulated body fluid (SBF) for one week to measure the variation in mechanical properties. The formation of the Hydroxyapatite and in-vitro results are provided and discussed

    Genome sequences of six Phytophthora species threatening forest ecosystems

    Get PDF
    AbstractThe Phytophthora genus comprises of some of the most destructive plant pathogens and attack a wide range of hosts including economically valuable tree species, both angiosperm and gymnosperm. Many known species of Phytophthora are invasive and have been introduced through nursery and agricultural trade. As part of a larger project aimed at utilizing genomic data for forest disease diagnostics, pathogen detection and monitoring (The TAIGA project: Tree Aggressors Identification using Genomic Approaches; http://taigaforesthealth.com/), we sequenced the genomes of six important Phytophthora species that are important invasive pathogens of trees and a serious threat to the international trade of forest products. This genomic data was used to develop highly sensitive and specific detection assays and for genome comparisons and to make evolutionary inferences and will be useful to the broader plant and tree health community. These WGS data have been deposited in the International Nucleotide Sequence Database Collaboration (DDBJ/ENA/GenBank) under the accession numbers AUPN01000000, AUVH01000000, AUWJ02000000, AUUF02000000, AWVV02000000 and AWVW02000000

    New Limits on the Low-frequency Radio Transient Sky Using 31 hr of All-sky Data with the OVRO-LWA

    Get PDF
    We present the results of the first transient survey from the Owens Valley Radio Observatory Long Wavelength Array (OVRO–LWA) using 31 hr of data, in which we place the most constraining limits on the instantaneous transient surface density at timescales of 13 s to a few minutes and at frequencies below 100 MHz. The OVRO–LWA is a dipole array that images the entire viewable hemisphere with 58 MHz of bandwidth from 27 to 84 MHz at 13 s cadence. No transients are detected above a 6.5σ flux density limit of 10.5 Jy, implying an upper limit to the transient surface density of 2.5 × 10⁻⁸ deg⁻² at the shortest timescales probed, which is orders of magnitude deeper than has been achieved at sub-100 MHz frequencies and comparable flux densities to date. The nondetection of transients in the OVRO–LWA survey, particularly at minutes-long timescales, allows us to place further constraints on the rate of the potential population of transients uncovered by Stewart et al. From their transient rate, we expect a detection of 8.4^(+31.8)_(-8.0) events, and the probability of our null detection is 1.9^(+644)_(-1.9) x 10⁻³, ruling out a transient rate >1.4 × 10⁻⁴ days⁻¹ deg⁻² with 95% confidence at a flux density limit of 18.1 Jy, under the assumption of a flat spectrum and wide bandwidth. We discuss the implications of our nondetection for this population and further constraints that can be made on the source spectral index, intrinsic emission bandwidth, and resulting luminosity distribution

    When Antibiotics Fail: The Expert Panel on the Potential Socio-Economic Impacts of Antimicrobial Resistance in Canada

    Get PDF
    Antimicrobials are life savers in Canada, enabling modern healthcare and playing a central role in agriculture. They have reduced the economic, medical, and social burden of infectious diseases and are part of many routine medical interventions, such as caesarean sections, joint replacements, and tonsillectomies. As use of antimicrobials has increased, bacteria evolved to become resistant, resulting in drugs that are no longer effective at treating infections. Antimicrobial resistance (AMR) is increasing worldwide, and with widespread trade and travel, resistance can spread quickly, posing a serious threat to all countries. For Canada, the implications of AMR are stark. When Antibiotics Fail examines the current impacts of AMR on our healthcare system, projects the future impact on Canada’s GDP, and looks at how widespread resistance will influence the day-to-day lives of Canadians. The report examines these issues through a One Health lens, recognizing the interconnected nature of AMR, from healthcare settings to the environment to the agriculture sector. It is the most comprehensive report to date on the economic impact of AMR in Canada

    Generations Active Together: an example of using physical activity promotion and digital technology to bring together adolescents and older people in Stirling, Scotland

    Get PDF
    The Generations Active Together (GAT) program, delivered by Active Stirling in central Scotland, is an intergenerational physical activity (PA) program for adolescents in high school and older adults in care homes and community groups. The Generating Older Active Lives Digitally (GOALD) Research Team sought to use GAT to examine how digital technology developed for the purpose of PA and sports-based reminiscence can be used to improve social connectedness for older adults. This paper details the challenges and successes of delivering the GAT program and describes the differences between in-person pre-pandemic delivery of GAT with the attempted digital delivery during the pandemic. The transferable lessons learned from GAT delivery to GOALD project planning and implementation included, but are not limited to, the importance of in-person activities for both generations and using digital technology as a complementary, rather than a replacement tool for PA delivery. CONTRIBUTION TO THE FIELD Intergenerational activities focusing on PA involving adolescents and older adults is possible with attention to reciprocal inputs and benefits for all generations and are potentially more effective and easier to deliver in person. Where in-person PA delivery is impossible, digital-only PA is arguably better than no interaction but requires support in setting up technology to deliver PA effectively. Digital technology is likely to be more effective in supporting intergenerational PA when complemented by in-person interactions. Adolescents and older adults in care homes can engage in beneficial interaction, but attention should be paid to school commitments at this age and stage, as well as the practical aspects of travel and scheduling of this kind of contact

    Deep Underground Science and Engineering Laboratory - Preliminary Design Report

    Full text link
    The DUSEL Project has produced the Preliminary Design of the Deep Underground Science and Engineering Laboratory (DUSEL) at the rehabilitated former Homestake mine in South Dakota. The Facility design calls for, on the surface, two new buildings - one a visitor and education center, the other an experiment assembly hall - and multiple repurposed existing buildings. To support underground research activities, the design includes two laboratory modules and additional spaces at a level 4,850 feet underground for physics, biology, engineering, and Earth science experiments. On the same level, the design includes a Department of Energy-shepherded Large Cavity supporting the Long Baseline Neutrino Experiment. At the 7,400-feet level, the design incorporates one laboratory module and additional spaces for physics and Earth science efforts. With input from some 25 science and engineering collaborations, the Project has designed critical experimental space and infrastructure needs, including space for a suite of multidisciplinary experiments in a laboratory whose projected life span is at least 30 years. From these experiments, a critical suite of experiments is outlined, whose construction will be funded along with the facility. The Facility design permits expansion and evolution, as may be driven by future science requirements, and enables participation by other agencies. The design leverages South Dakota's substantial investment in facility infrastructure, risk retirement, and operation of its Sanford Laboratory at Homestake. The Project is planning education and outreach programs, and has initiated efforts to establish regional partnerships with underserved populations - regional American Indian and rural populations
    corecore